Furnace.



1. MCKENNA. FuRNAcE. APPLICATION FILEDAPR.22, 1915.

Patented Sept. 26,1916,

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A TTORNE YS,

UNITED STATES PATENT OFFICE.

JOSEPI-I IVICKENNA, 0F FORT WAYNE, INDIANA, ASSIGNOR TO THE FORT WAYNE ROLLING MILL CORPORATION, OF FORT WAYNE, INDIANA, A CORPORATION.

FURNACE.

To all 107mm t may concern Be it known that I, JOSEPH MC-KENNA, a citizen of the United States, residing at Fort lVayne, in the county of Allen and State of Indiana, have invented new and useful Improvements in Furnaces, of which the following is a specication.

The invention relates to furnaces and particularly to rolling mill furnaces wherein oil or powdered coal is used as the fuel. In all such types of furnaces it is essential that a blast of air be provided withthe oil or coal and one of the troublesome features of such use of air is that it is generally cold or the temperature of the outside air and therefore tends to lower the temperature of the heating chamber as it is blown into that chamber. The temperature of the heating chamber is necessarily kept very high in rolling mill usage and any cooling agent admitted to it is accordingly objectionable. Numerous attempts have been made heretofore to heat the air before it reaches the combustion chamber of the furnace as, for example, installing the air pipe in the walls of the combustion chamber of the furnace, also in the rear end of the furnace adjacent the exhaust or smoke stack, the purpose being that the air as it is driven through the pipe installed as just described, will be warmed and thereby aid the combustion of the fuel much more effectively than when it is in the cold state. Such installations of the pipe have many objections, the pipe is inaccessible for cleaning purposes and is rapidly disintegrated and is slow to become effective for heating the supply of air and its installation in the rear end of the furnace prevents the use of the waste heat of the furnace for heating the steam boiler. It is common practice in rolling mills to make use of the waste heat of the furnaces for heating the steam boilers of the plant, and any attachment' to the furnace which will interfere with or destroy the effectiveness of the waste heat for that purpose is highly objectionable and uneconomical.

The object of the invention is to provide a furnace with means for preheating the air supplied to it which shall be at all times accessible, shall have long life and interfere with no part of the furnace nor with its proper working or with the use of its waste heat, and greatly reduce the fuel consumption during initial heating of the furnace.

Specification of Letters Patent. Patented Sept. 26, 1916.

Application 1ed`Apri122, 1915.

Serial No. 23,034.

Another object is to provide van adjustable discharge nozzle for the fuel in order that the direction of discharge of the fuel may be changed from time to time as desired.

In the accompanying drawings I illustrate one manner in which my invention may be carried out in practice, Vand in which- Figure 1 is a longitudinal sectional view of a fraction of a furnace equipped with the invention; Fig. 2 an end view of the discharge nozzle, Fig. 8 a longitudinal sectional view of the nozzle; Fig. l a sectional view on line H of Fig. 1, and Fig. 5 a plan view of the head of the furnace.

. Referring to the, drawings, the furnace illustrated is intended for use with powdered coal as the fuel, the only change necessary, when oil is used, being that of providing a suitable nozzle for the discharge of the oil.

The combustion chamber 10 of the furnace is provided by the brick side walls 11, arched top 12, grate bars 13, vertical cross wall 11i and front wall 15. The usual coke breeze 16 is vprovided on the grate bars 13 and rearwardly of the wall 14C is the heating chamber, the top of which is usually curved rearwardly and the bottom 17 of which slopes downwardly from the wall 14 toward the foundation, the curved top and sloping bottom finally form-ing a restricted opening for the dischargeof the waste heat into the conduit to the stack. The portions of the furnace rearwardly ofthe wall 14; form no part of my invention, hence I do not illustrate them.

At a suitable point in wall 15 anV opening 18 is provided into which is fitted one end of the pipe 19, the other Vend of the pipe being closely fitted into ank opening pro-v vided in a vertical wall 2O which is spaced a suitable distance forwardly of wall l5. An arch 21 connects the two walls 15 and 2O at the top, a stack 22 being connected to the top of the arch and having a suitable check 22a arranged in it for controlling the escape of gases from the chamber 23 formed by the said two walls and arch. Grate bars 24 are removably arranged in the bottom of chamber 23 and one or more layers of brick 25 are arranged on the bars. A suitable number of apertures 26 are provided in wall 1 5 in itsupper portion and preferably on oppositeH sides of opening 1S. The purpose of these openings is to permit the heat Within chamber 10 to-iadiate and refleet into 'chamber' 23.

Within chamber 23 is arranged a plurality of pipes 27, 28, 29 which project through the opposite side walls of. the chamber and are connected successively" eXteriorly of the said Walls by unions 80, so thaft'theyv provide :af

continuous conduit for the passage of aii through thechamber '23, the air-entering through ipipe 27vandv passing-.through the'r several@ pipes :and finally passing through union 31, pipe 32,'pipe 33 'andunion 34 into pipe 19, from which it is dischargedinto chamber 10 :'alongi WithL :thenpoivdered coal which -is blasted'through nozzlexu A suit-.l

able gate valve maybe arranged in pipe 321for controlling the supply of ivarmnair to chamber 10.`

If it isdesired pipes 37 and BSSmay -beplaced infthe cokefbreeze -,16,"the opposite"v ends of the pipesI proj ectingtlirough thesidef Walls of the furnace# Two ofsaid endsaref connected by pipe 39,'-the other end of'pipeA 38 being connected I'by suitableunions tothe free end of 'pipe 27 and a blower' being connected to the free endof pipe 37. Orlpipes 37 and .38' may be :omitted and the blowerl connected tothe free'end of pipe'27; Theheat' rivithin ithe breeze if V16 1and lthat Within chamber 23 andthe heat thereof Whi'ch'has beentransmitted through the Wall`- itself, will cause the severalzpipes to become 'hot andY consequently*Warm-the air'v as it passes through L chenal Ifi 'pipes "37 f andfBSf are omittedJthe f pipes Within" chamber 23 'l will thenvr furnish the desired heated air.

Doors 39a are provided in vthe front Wall ofchamber 2id-'Which furnish 'access'fto that chamber.

Nozzle 'isiconnected at-oneiend to -a fuel supply pipe 40,' the connection 4beingsoinewhat loosefso that the nozzle may -befmovedl uponl the :pipe :40 as a pivot tofchange" the direction ofl its longitudinal? aX-is so=that the direction ofthe dischargeof the fuel maybe controlled as desired. To enable the fnozzle to bereadily adjusted I provide'fa lever 41 whichv is pivotally mounted upon'a support 42 which support is-inovablysecured to-the` bottom-of `"pipe 19 -by a vbolt 13 Which is threaded through' theA said bott om. i One end of e thelever 41 is Ybifurcated orfprovid'ed withV al clevis 4:4 in' Which rests the forward end of the nozzle. l A'braclieta bentV intheformof `a right angle lis secured tol the rear-- end offleve'r41- and each arm of the bracket is slotted or bifurcate'd and'tivo 'adjustable' bolts 46 andl' are threaded through the Wallof pipe 19,'the inner ends'of the boltshaving annular recesses inftheir peripheries in Vwhichrecesses the-bifurcated arms `of bracket engage. Itis vapparent 'that Vthe nozzle iiiay bej tilted in vvvertical plane by It is :also apparent :thatwby providing the stack Q2 for chamber QBVthe hcatof the com bustion chamber 10 maybe more readily; conducted: intoV chamber r Q3: in starting. lthe .fu-r

nace, but thedamper inf'said'stack will be closed `more-zer less normal operationfof the furnace,Vv in .order that 1 the heated gases-V shallnot beiwastede The-.stack also-greatly reduces.: the fuel coiisuinption=` in" initially n heating up the furnace,isince,inf startingup,y

thehdamper :in thek main stack Willi beA4 closed and that -1in= stackr'ivill ibe opened vtherebycompelling; the lgases f of= the combustion chamber toy passeront vtliroughy stack-22I and very quickly heating up .the air conduits in chamber '23: so,` that Warmnair is supplied almostfiinimediately 'after-starting iipthe` furnaces p That l claim fis: 1 1.!Thef combinationA off a; combustio chamber. having :communication at Vone end With ia staclnfa perforated :vertical-1Wallat:` the opposite vlend of: the combustion chainber, asecond vertical Wall ,forwardly of theperforated'y Wall? and exteriorly of the coin.

bust'ionv chamber, a conduit' =betiveeii the tWo vertical Walls and adapted to-beiheated byy reected heat from thel combustion chamber and a dischargel fpipecommunicating vwith the combustion chamber and having conne@Y tion'ivitli the conduit, the conduit also hav-v ing communication with outside airu 2. The combination.- of ay combustion? chamber havin-g communicationV -at 'one -end with a stack,` a perforated vertical Wall'vaty the opposite yend of the combustion chamber,=a ydischarge "pipe supported lin the Wall Y and communicating ywith the 'combustion chamber, a =vertical Wall forwardly f of the perforated`vr lWall, 5 Walls l' connecting y'thel-tivo-V verticale-Valls to formi-a chamber therebetvveen, and exterior ofthe combustion cham.-

ber,"a. conduit Within Ithe-latter chamberhaving communication-'With *outside air and having connection with the discharge vpipe,

the perforated-'Wallv being-adapted to admit reflected -he'at and hotv gases from the com bust'ioni chamber "into fthe conduit chamber for heating the lconduit and Imeans inthe'- discharge pipe for'f'admitting" fuel'fto the combustion chamber.

3. The" combination' of=` a combustion chamber having communication at fone endy iio with a stack, a perforated vertical wall at the opposite end of the combustion chamber, a discharge pipe supported in the wall and communicating with the combustion chamber, a vertical wall forwardly of the perforated wall, walls connecting the two vertical walls to form a chamber therebetween and exterior of the combustion chamber, a stack connected to one of the walls of the latter chamber', a damper in the stack, a conduit within the latter chamber having communication with outside air and having connection with the discharge pipe, the perforated wall being adapted to admit reiected heat and hot gases from the combustion chamber into the conduit chamber for heating the conduit and means in the discharge pipe for admitting fuel to the combustion chamber.

et. In a furnace the combination with a combustion chamber, a coke breeze in the bottom of the combustion chamber, a conduit for outside air under pressure extending through the breeze and projecting eX- teriorly of the furnace, a second chamber adjacent the combustion chamber and having communication therewith and adapted to be heated thereby, a discharge pipe for air having communication with the combustion chamber, a conduit within the second chamber having connection with the first mentioned conduit and the discharge pipe, and a nozzle within the discharge pipe for the discharge of fuel into the combustion chamber.

In witness whereof I hereunto subscribe my name this th day of April, 1915.

JOSEPH MCKENNA.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents. Washington, D. C. 

